... & Cleaness White sheet surface,fiber is average,no gravel and metalic powder,even sheet texture ≤1 for mechanical impurity(≥0 ... impurity(≥2mm) White sheet surface,fiber is average,no gravel and metalic powder,allow 0.5mm organic Impurity. 2 Tensile ... circular barrels outside,on the barrel,there should be attached label and quality certificate,on which there are brand,trademark,executive criterion ...